The present invention relates to ink supplies for an ink-jet printer and, more particularly to ink supplies that can be readily refilled or replenished. A typical ink-jet printer has a print head mounted to a carriage that is moved back and forth over print media such as paper. As the print head passes over appropriate locations on the printing surface, a control system activates ink jets on the print head to eject, or jet, ink drops onto the printing surface and form desired images and characters.
To work properly, such printers must have a reliable supply of ink for the print head. Many ink-jet printers use a disposable print cartridge that can be mounted to the carriage. Such a print cartridge typically includes, in addition to the print head, a reservoir containing a supply of ink. The print cartridge also typically includes pressure-regulating mechanisms to maintain the ink supply at an appropriate pressure for use by the print head. When the ink supply is exhausted, the print cartridge is disposed of and a new print cartridge is installed. This system provides an easy, user-friendly way of providing an ink supply for an ink-jet printer.
Other types of ink-jet printers use ink supplies that are separate from the print head and are not mounted to the carriage. Such ink supplies, because they are stationary within the printer, are not subject to all of the size limitations of an ink supply that is moved with the carriage. Some printers with stationary ink supplies have a refillable ink reservoir built into the printer. Ink is supplied from the reservoir to the print head through a tube that trails from the print head. Alternatively, the print head can include a small ink reservoir that is periodically replenished by moving the print head to a filling station at the stationary, built-in reservoir. In either alternative, ink may be supplied from the reservoir to the print head by either a pump within the printer or by gravity flow.
Once depleted, the reservoir is typically discarded and a new reservoir installed. However, the reservoir and any associated mechanisms are typically capable of further use if they could be replenished with a fresh supply of ink.